* Introduced more accurate timing for NTSC vs. PAL modes, where the framerate is based on the number of scanlines per frame. This should eliminate 'clicking' sounds when emulating ROMs that don't follow the exact NTSC or PAL scanline specs.

* Added ability to see the current number of scanlines and corresponding framerate to the TIA emulation. This can be set with the '-stats' commandline argument, or dynamically turned on and off with the 'Alt-l' key combo.

* Modified '-framerate' commandline argument, where a non-zero value overrides the automatic framerate calculation (based on number of scanlines). Setting 'framerate' to zero re-enables auto-frame calculation. Also, re-enabled changing the framerate from within the UI.

* Added '-timing' commandline argument, which sets the type of waiting between processing frames. Setting it to 'sleep' emulates the previous behaviour in Stella; setting it to 'busy' emulates z26, and can in some cases eliminate screen tearing (at the expense of using all available CPU time).